Automatic engine starter



Sept. 27, J VANCHA AUTOMATIC ENGINE STARTER Filed March 26, 1964 United States Patent O 3,275,836 AUTOMATIC ENGINE STARTER `lohn Vancha, Chicago, Ill., assgnor of one-half percent to Frederick A. Michaels, Chicago, Ill. Filed Mar. 26, 1964, Ser. No. 354,902 6 Claims. (Cl. 290-38) This invention relates generally to an automatic starting system for engines, and more specifically to an automatic electrical control system for starting internal combustion engines on motor vehicles.

Although the principles of the present invention may be included in various devices employing internal combustion engines, a particularly useful application is made in motor vehicles. The system may be constructed in a manner in which it is fully integrated into the known types of electrical systemsk now employed, or it may be constructed as a separate device having .appropriate adaptation as by terminals for installation in or attachment to the electrical system of such an engine.

It yhas been previously suggested that a system should be provided to start an engine automatically as a function of a predetermined temperature or as a function of the elapse of a, predetermined period of time. In such systems, the -ignition has @been turned on automatically, the starting circuit has been energized, engine operation has been sensed to terminate operation of the starting circuit, the vehicle yheater has been energized, and the system has been shut down upon the attainment of a -predetermined temperature or time. Prior systems have been characterized `by excessive complexity in that they have involved a large number of components, many of which have been of a mechanical nature, usually requiring lubrication, and hence not suitable for extreme low-temperature starting. lt has also been considered impractical previously to employ as a thermal sensing element any component which changes its resistance as a function of temperature since battery voltage varies widely depending upon its state of charge, its temperature, and on whether the engine is running. Further, in prior systems, there has usually been a considerable reaction time required in the automatic sensing of whether the engine has started, and it has been impractical previously to provide a system which would automatically attempt a restart of the engine in the event that it dies soon after starting.

In accordance with the principles of the present invention, I have provided a structure which employs a minimum of parts, which is all-electrical in operation, and which overcomes all of the aforementioned difficulties.

Accordingly, it is an object of the present invention to provide an improved automatic starting control system for an internal combustion engine.

Another object of the present invention is to provide a control system of the type described in which all of the components are electrically operated devices.

A further object of the present invention is to provide a system of the type described in which `battery voltage variations will have a minimum effect on the control of startanother object of the present invention `is to provide a system of the type described which avoids all of the problems and failures incidental to the use of mechanical components, including lubrication, so that the system will be operative at extremely low temperatures.

Yet another object of the present invention is to pro- ICC vide a structure in which any manual reset is unnecessary, even if there has been a failure in starting.

Yet another object of the present invention is to provide `a system of the type described in vwhich the response to a stalled engine and restarting thereof is substantially instantaneous, particularly during the first few minutes of operation.

A still further object of the present invention is to provide a system of the type described in which operation of the starting circuit is terminated as soon as the engine starts.

Many other advantages, features and additional objects of the Ipresent invention will become manifest to -those versed in the art upon making reference to the detailed description and the accompanying sheet of drawings in which a preferred structural embodiment incorporating the principles of the present invention is shown by Way of illustrative example.

On the drawing:

The drawing shows diagrammatically and schematically an automatic starting control system constructed in accordance with the principles of the present invention.

As shown on the drawing:

The priciples of this invention are particularly useful when embodied in' an automatic starting control system for an internal combustion engine, such system being illustrated by the drawing, and being generally indicated by the numeral 10. The control system 10 is constructed to be employed with the electrical system of a motor vehicle, operating parts of which are shown to the extent necessary to illustrate the connections and relationships between the automatic starting control system and the elecrical system generally. The electrical system of a motor vehicle is known to include components such as a battery 11, an electrical termperature-indicating gage 12, an ignition circuit 13, a start-ing circuit generally indicated at 14, a heater blower circuit 15, and a means generally indicated at 16 described lmore fully 4below and which may comprise a portion of the generator armature winding or a portion of the voltage regulator.

For purposes of illustration, the battery 11 comprises a 12-volt battery, the negative side of which is grounded. (The `bat-tery may be reversed if suitable attention is paid to polarity elsewhere). The normal battery voltage when the engine is operating may vary considerably due to the effect of the voltage regulator, and due to differences between voltage regulators. Further, the temperature and state of charge of the battery also affect the voltage available therefrom. The battery 11 is connected through a switch 17 which is so mounted that it is closed Whenever the transmission shift lever is either in a neutral or in a parking position. Conversely, the switch 17 is open for safety reasons whenever the shift lever is in any driving position. The shift lever switch 17 is connected in series with a switch 18a which forms one section of a multipole switch or which is ganged to operate with other switches identified below by the numeral 18, but having different suffix letters. The on-off switch 18 is connected to a constant voltage supply circuit 19 which is connected toa current-sensitive relay 20, which is connected through a selector switch 18b to a thermal or temperature-sensing element 22. To this end, the constant voltage circuit 19 includes a resistor 23 connected in series with one side of a Zener diode 24, the other side of which is grounded.-

A line 25 connects a point between the resistor 23 and the diode 24 to one side of a coil 26 of the current- Sensitive relay 20, the other side of such coil being connected to one of the terminals of the selector switch 1811 as shown. The constant voltage circuit 19 provides a potential which remains within one percent of ten volts which is thus applied across the coil 26 and the temperature-sensing element 22. The temperature-sensing element 22 comprises .an electrical resistance which has a negative coefficient of thermal resistivity so that its resistance is inversely proportional to temperature. The sensing element 22 is the one which may be normally used for operating the temperature-indicating gage 12 when the selector switch 181; is in the position drawn. However, when the switch 18b is moved to its other position, the sensing element 22 is connected in series with the coil 26. Under normal conditions, when power is applied through the switches 17, 18a, constant voltage circuit 19, line 25, coil 26, selector switch 18h, andv sensing element 22, suicient current will flow therethrough to operate the relay 20, thereby opening its set of normally closed contacts 27.V When the temperature drops to `a predetermined level, the electrical resistance of the sensing element 22 increases until a predetermined value is reached at which value, the relay 20 drops out, thereby closing the lnormally closed contacts 27. The contact voltage in the line 25, the current-sensitive relay 20, and the sensing element 22 are so selected that the temperature of the sensing element 22 causes the relay 20 to close when desired. Closing of the normally closed contact 27 controls operation of a relay circuit generally indicated at 28 which is connected as described below to deliver power to the starting circuit 14.

It is preferred that a capacitor 29 be connected across the normally closed contacts 27 to protect the same against damage due to arcing.

Under certain circumstances, rather than use a predetermined condition of temperature, it will be advantageous to use a predetermined condition of time. To this end, there is provided a motor-driven switch 21 having a normally |open set of contacts 30 connected in parallel with the normally closed contacts 27. A manual switch 31 Vmay be used to isolate the contacts 27 from ground by opening the same, as drawn. A terminal 32 is grounded in response to closing of the normally closed contacts 27 of the current-sensitive relay 20 whenever the switch 31 is closed. The same terminal 32 is grounded whenever the motor-operated switch or timer 21 closes its contacts 30. The motor-operated switch or timer 21 may be constructed so as to close its contacts 30 periodically, for example at intervals of fifteen minutes, or the same may be constructed to close the contacts 30 steadily after elapse of a preset time interval. If the switch 31 be open, there can be no intervening starting of the engine, while if the switch 31 is closed, the attainment of a predetermined temperature will effect intervening operation of the engine.

In normal operation, the ignition circuit 13 is controlled by a key-governed switch 33. The regular ignition switch 33 is shunted or bypassed by a line 34 leading through a switch 18C lto a set of normally open contacts 35 forming a part of 4an ignition relay 36. One of the contacts 35 is connected to a buss line 37 leading from the ori-off switch 18a to various elements as shown. With the relay 36 not energized, power thus cannot be brought to the ignition circuit 13, but upon closing of the relay 36, the ignition circuit 13 is energized.

The relay circuit 28 includes the ignition relay 36, a starter relay 37, a cutout relay 38, a thermal cycling switch 39, a `second thermal switch 40, and such interconnections and wiring as is shown and described.

The starting circuit |14 includes a conventional starter or starting motor 41 which is under the controlrof a starter solenoid 42 which is normally operated by the usual starter switch 43. T-he power buss or yline 37 is connected through a pair of normally open contacts 44 in the ignition relay 36, through 4a line 45, to a pair of normally open contacts 46 in the starter relay 37. When both the ignition relay 36 and the starter relay 37 are in :an energized position, then both the contacts 44 and the contacts 46 are :closed so that power is delivered in bypassing relation to the starter switch 43 to the starter circuit 14 to energize the starter solenoid and to operate the starter motor 41. Upon opening either of the ignition relay 36 or the starter relay 37, power to the starter is interrupted. Y

Whenever power is interrupted to the starting circuit 14 by the relay 37, a further normally closed set of contacts 47 conducts power through a line 48 to a normally closed set of contacts 49 in the cutout relay 38.

Whenever the cutout relay 38 has been energized as described below, due to starting of the engine, power lfrom the line 48 passes to a set of normally open contacts 50 and thence through aline 51 leading to the heater blower motor circuit 15 in bypassing relation to a switch 52 which is normally used for manual control of the heater motor.

The cutout relay 38 has a coil 53 which is connected through a switch 18d across the coil or portion 16 of the electrical :system of the engine. The lporti-on or means 16 may comprise a generator armature coil or a voltage regulator coil such as is a part of contemporary electrical systems of motor vehicles. The switch 18d is thus merely connected to such portion thereof as develops a suicient potential in response to starting of the engine to operate the cutout relay 38. The potential across the -means 16 during cranking of the engine is insufficient, if any, to operate the cutout relay 38.

The ignition relay 36 has a coil 54, one side of which is connected to the terminal 32 for grounding by the contacts 27 or 30, and the other side of which coil 54 is connected through a pair of normally closed contacts 55 forming a part of the thermal switch 40, to the power line 37. Thus, with the switches 17, 18a, and 31 closed, when the relay contacts 27 close, they effect grounding of the terminal 32 and hence the closing of the circuit through the coil of the ignition relay 36 to energize the ignition circuit 13 and to bring power to the line 45. This also brings power through the normally closed contacts 47, the line 48, and the normally closed contacts 49 through a line 56, through an electrical heater 57 forming a part of the thermal cycling switch 39, and through a resistor 58 to complete a circuit through the heater 57.

Energizing of the line 37 also brings power through a pair of normally closed contacts 59 in the unenergized cutout relay 38 which are connected by a line 60 to one side of a coil 61 of the starter relay 37. The other side of the coil 61 is connected through a line 62 to a pair of normally open contacts 63 in the thermal cycling switch 39, for completing the circuit. Thus, the open contacts 63 prevent initial operation of the starter relay 37. However, as heat is given o by the heater 57, the contacts 63 are caused to close in response thereto, thereby closing the starter relay 37. Doing so brings power through the normally open contacts 46 to the starting circuit 14 as described above. This also opens the normally closed contacts 47, thereby interrupting current through the heater 57 of the thermal switch 39. Upon cooling, the thermal switch 39 opens its contacts 63, thereby opening the coil circuit of the starter relay 37, to thereby terminate cranking. However, thi-s recloses the normally closed contacts 47 to cause reheating of the heater 57 and subsequent reclosing of the contacts 63 of the thermal switch 39, and energization of the coil of the starter relay 37, which thus provides a second or next attempt to start the engine by energizing the starting circuit 14. Such cycling continues periodically until interrupted. The initial closing of the contacts 63 typically may take one minute. They typically remain closed about live seconds and open for five seconds, thus going through a ten-second cycle` with about 50% on time.

aes/5,5136

As soon as the engine starts, a potential from the means 16 is applied to the coil 53 of the cutout relay 38 as described which causes opening of the normally closed contacts 59 to terminate instantly the closed condition of the starter relay 37 if it then be energized. The energizing of the cutout relay 38 also opens the normally closed contacts 49 to prevent further heating of the heater 57 in response to the closing of the contacts 47 when the sta-rter relay 37 is deenergized.

The cycling of the thermal switch 39 may also be terminated by the second thermal relay 40 which serves as a fail-safe device to shut the system down, namely to terminate cranking, in the event that the engine fails to start within a reasonable time. To this end, the thermal switch 4() includes an electrical heater 64 which is connected to the power line 37 through a resistor 65 arranged in series therewith, the other side of the serially connected heater 64 and resistor 65 being connected to the terminal 32 for grounding as described. When the normally closed contacts 27 are closed by dropping out of the current-sensitive relay 20, or when the contacts 30 are closed by the timer 21, heater current passes through the resistor 65 and the heater 64 continually for a predetermined period of time, such as 180 seconds, to heat the thermal elements which thus ultimately open the normally closed contacts 55. When these contacts open, the cutout relay 38 being deenergized, power is disconnected from the coil 54 of the ignition relay 36 to open the line 34 leading to the ignition circuit 13 and to deenergize the line 45 and hence both the heater 57 of the thermal switch 39 if the starter relay 37 is deenergized and the starting circuit 14 if the starter relay 37 is then energized. In the example given, thus there will be approximately 12 iivesecond attempts made to start the engine, after which further attempts to start the engine are discontinued to protect the battery 11. Once the switch 17 of 18a has been opened, the heater 64 wil-l cool and be ready to function once more. When the engine starts, and through the means 16 effects energizing of the cutout relay 33, a pair of normally open contacts 66 leading to a line 67 are clo-sed, the line 67 thus comprising a holding circuit connected to one side of the coil 54 of the ignition relay 36 to hold the same energized, even lthough the contacts 55 may open. In the event that the engine dies before the contacts 55 have opened, the cutout relay 38 will drop out, and the cycling of the starter relay 37 by the thermal switch 39 will continue. Thus, attmepts will be made automatically to restart a stalled engine during the predetermined period of time controlled by the thermal switch 40 for opening the contacts 55.

When the starting solenoid 42 is not energized so that the starter motor 41 is not drawing current from the battery 11, the voltage on the line 37 will ordinarily be about 12 volts. However, when the st-arter 41 is energized, this voltage drops to about half that value. The thermal switch 40 is preferably selected so that the heater 64 thereof should normally be provided with about six volts. The resistor 65 thus serves as -a voltagedropping resistor to maintain the proper potential on the heater 64 when the starter 41 is not energized. There is provided a shunt circuit 68 connected across the resistor 65, the shunt circuit 68 including a line 69 and a pair of normally open contacts 70 in the starter relay 37. Whenever the starter relay 37 is clo-sed to operate the starting circuit 14, the shunt circuit 68 is also closecircuited, thereby shunting or shorting out the resistor 65 so that the voltage then present on the line 37 appears at the heater 64 in the thermal switch 40; Thus, the potential applied to the heater 64 remains relatively constant, even though cycling o-f the starting circuit 14 may be taking place.

While the switches 18a 1819, and 18d provide the necessary isolation between the system 10 and the electrical system of the engine, the switch 18C serves to prevent an unwanted feedback therethruogh so as to prevent energization of the line 37 through the switch 33 if the switch 33, in the absence of fa switch 18C, were moved to a closed circuit position when the engine was running with control power received through the switches 17 and 18a.

The following represent typical values or components which may be employed in the practice of this invention:

R23 120 ohm, 1 watt R58 10 ohm, 20 wattV R 10 ohm, 20 watt Diode 24 Zener, 10 volt, 1 watt Relay 20 Sigma 11 F550 Relays 36, 37, 38, 42 12 volt coils C29 1-100 mfd. Thermal Switch 39 Amperite 6NO60T Thermal Switch 40 Amperite 6C180T From the foregoing it should now be understood that the constant voltage circuit 19 maintains a substantially constant voltage across the serially connected coil 26 and sensing element 22 so that when the thermal element 22 is subjected to a temperature decrease to a predetermined value, the current flow in the relay coil 26 will lessen to effect self closing of the contacts 27 for operating the relay circuit 28. By this structure, allelectrical means are provided in a simple and facile manner. Moreover, the thermal sensing element 22 may be employed both for the` temperature gage 12 on the instrument panel of the vehicle, and as the conditionresponsive means for controlling starting. Such shared usage of this element contributes to the structural economy thereof. Further, the thermal relays 39 and 40 thus provide cycling of the starter relay 37 for a predetermined period of time which cycling is resumed during such period of time in the event that the engine should stall. Such resumption of cycling is aided by the use of a portion of the vehicles electrical system which is responsive to engine operation, and to that end provides a potential for energizing the cutout relay instantaneously in the event of engine starting, such means 16 further providing for the instantaneous dropout of such cutout relay n the event of engine stalling during such predetermined period. Further, the shunt circuit 68 connected in parallel with the resistor 65, which is in series with the heater 64 insures a substantially constant voltage on the heater 64 thus facilitating predetermination or selection in a facile manner of a suitable component in a particular installation.

Although various minor modifications might be suggested by those versed in the art, it should be understood that I Wish to embody within the scope of the patent warranted hereon all such embodiments -as reasonably and properly come within the scope of my contribution to the art.

I claim as my invention:

1. In an automatic starting control system for an internal combustion engine having a battery and a starting circuit powered thereby, the combination comprising:

(a) a thermal sensing element having an electrical resistance responsive Ito temperature, and adapted to sense engine temperature;

(b) a current-sensitive relay having a coil connected in series with said thermal sensing element, and a set of contacts;

(c) a constant voltage circuit adapted to be powered by the battery, and connected in series with said coil and said thermal sensing'element; and

(d) a relay circuit under the control of said contacts and adapted to be connected to the engine starting circuit for controlling application of power thereto.

2. In an automatic starting control system for an internal combustion engine having a battery and a starting circuit powered thereby, the combination comprising:

(a) a thermal sensing element having an electrical resistance inversely proportional to temperature,

and adapted to sense engine temperature;

(b) a current-sensitive relay having a coil connected in series with said thermal sensing element, and a normally closed set of contacts;

(c) a constant voltage circuit adapted to be powered by the battery, and connected in series with said coil and said thermal sensing element; and

(d) a relay circuit under the control of said contacts and adapted to be connected to the engine starting circuit for controlling application of power thereto;

whereby a temperature decrease of said thermal element to a predetermined value lessens the current ow in said relay coil to effect self closing of said contacts for operating the relay circuit.

3. In an automatic starting control system for an internal combustion engine having a battery, an engine starting circuit powered thereby, and electrical temperature-indicating gage means, the combination comprising:

(a) a thermal sensing element having an electrical resistance responsive to temperature, and adapted to sense engine temperature;

(b) `a current-sensitive relay having a coil and a set of contacts;

(c) a selector switch which, `in one position, connects said coil in series with said thermal sensing element, and in a second position is adapted to connect the gage means to said thermal sensing element;

(d) a constant voltage circuit adapted to be powered by the battery, and connected for applying a constant voltage across said coil and said thermal sensing element; and

(e) a relay circuit under the control of said contacts and adapted to be connected to the engine starting circuit for controlling application of power thereto.

4. In an automatic starting control system for an internal combustion engine having a battery and a starting circuit powered thereby, the combination comprising:

(a) means responsive to a predetermined condition and having a set of contacts;

(b) a relay circuit under the control of said contacts,

and including (l) a starter relay having a coil adapted to be connected at one side thereof to the battery, a set of normally open contacts operative when closed to apply power to the engine starting circuit and a set of normally closed contacts,

(2) a rst thermal switch for cycling said starter relay periodically, said thermal switch including an electrical heater connected to said normally closed contacts of said starter relay to receive power therefrom, and a pair of normally open contacts responsive to heat emitted by said heater and connected in series with the other side of said starter relay coil for completing the circuit to the battery, and

(3) a second thermal switch for limiting the duration of such cycling, and including an electrical heater connected in series with said rst named set of contacts and adapted therewith to be connected across the battery, and a pair of normally closed contacts responsive to heat emittei by said last named heater, and connected in said relay circuit to control delivery of power from the battery to said sets of starter relay contacts.

5.*In an automatic starting control system for an internal combustion engine having a battery and a starting circuit powered thereby, the combination comprising:

f (a) means responsive to a predetermined condition 1 and having a set of contacts;

(b) a relay circuit under the control of said contacts,

and including 'i (l) 'a starter relay connected to control application of power from the battery to the starting circuit,

(2) means operative to cycle said starter relay periodically,

(3) a thermal switch connected in said relay circuit to terminate the cycling of said starter relay, said thermal switch including an electrical heater connected in series with a resistor and adapted therewith to be connected across theV battery, and

(4) a shunt circuit connected across said resistor and including a set of normally open contacts in said starter relay.

6. In an automatic starting control system for an internal combustion engine having an electrical system including a battery, an engine starting circuit powered thereby, land electrical temperature-indicating gage means, the combination comprising:

(a)V a thermal sensing element having an electrical resistance inversely proportional to temperature, and adapted to sense engine temperature;

(b) a current-sensitive relay having a coil, and a nor mally closed set of contacts;

(c) a selector switch which, in one position, connects said coil in series with said thermal sensing element, and in a second position is adapted to connect the gage means to said thermal sensing element;

(d) a constant voltage circuit adapted to be powered by the battery, and connected for applying a constant voltage across said coil and said thermal sensing element;

(e) a relay circuit under the control of said normally closed contacts, and including (l) a starter relay having a -coil adapted to be connected at one side thereof to the battery, a set of normally open contacts operative when closed to apply power to the engine starting circuit, and a set of normally closed contacts,

(2) a first thermal switch for cycling said starter relay periodically, said thermal switch including an electrical heater connected to said normally closed contacts of said starter relay to receive power therefrom, and a pair of normally open contacts responsive to heat emitted by said heater and vconnected in series with the other side of said starter relay coil for completing the circuit to the battery,

(3) a second thermal switch for limiting the duration of such cycling, and including an electrical heater connected in series with a resistor and with said rst named set of contacts and adapted therewith to be connected across the battery, and a pair of normally cloced contacts responsive to heat emited by said last named heater, and connected in said relay circuit to control delivery of power from the battery to said sets of starter relay contacts,

(4) a shunt circuit connected across said resistor and including a set of normally open contacts in said starter relay, and

(5) a cutout relay having contacts operative on energization of the relay to terminate operation of the starting circuit, said cutout relay having a coil for being connected across a portion of the electrical system of the engine in which portion a relay-operating potential is developed in response to starting of the engine.

References Cited by the Examiner UNITED STATES PATENTS ORIS L. RADER, Primary Examiner. G. SIMMONS, Assistant Examiner. 

1. IN AN AUTOMATIC STARTING CONTROL SYSTEM FOR AN INTERNAL COMBUSTION ENGINE HAVING A BATTERY AND A STARTING CIRCUIT POWERED THEREBY, THE COMBINATION COMPRISING: (A) A THERMAL SENSING ELEMENT HAVING AN ELECTRICAL RESISTANCE RESPONSIVE TO TEMPERATURE, AND ADAPTED TO SENSE ENGINE TEMPERATURE; (B) A CURRENT-SENSITIVE RELAY HAVING A COIL CONNECTED IN SERIES WITH SAID THERMAL SENSING ELEMENT, AND A SET OF CONTACTS; (C) A CONSTANT VOLTAGE CIRCUIT ADAPTED TO BE POWERED BY THE BATTERY, AND CONNECTED IN SERIES WITH SAID COIL AND SAID THERMAL SENSING ELEMENT; AND (D) A RELAY CIRCUIT UNDER THE CONTROL OF SAID CONTACTS AND ADAPTED TO BE CONNECTED TO THE ENGINE STARTING CIRCUIT FOR CONTROLLING APPLICATION OF POWER THERETO. 